WO2014065568A1

WO2014065568A1 - Method for configuring wireless frame of user equipment and user equipment, and method for configuring wireless frame of base station and base station

Info

Publication number: WO2014065568A1
Application number: PCT/KR2013/009425
Authority: WO
Inventors: 김기태; 김진민; 고현수; 정재훈
Original assignee: 엘지전자 주식회사
Priority date: 2012-10-22
Filing date: 2013-10-22
Publication date: 2014-05-01
Also published as: EP2911320A4; EP2911320A1; KR20150091046A; JP6437918B2; EP2911320B1; US9743401B2; US20150264683A1; JP2016500964A; KR101617273B1

Abstract

Flexible employment of frame configuration in light of the Doppler frequency change is proposed. According to the present invention, frame configuration for a predetermined frequency band may be changed. Changing frame configuration in the present invention may include changing the number (≥0) of zero-power subcarriers which alternate with nonzero-power subcarriers.

Description

[Specification] ^'

[Name of invention]

Wireless frame setting method of user equipment and user equipment, Wireless frame setting method of user equipment and base station

Technical Field

The present invention relates to a wireless communication system. In particular, the present invention relates to a method and apparatus for setting a radio frame.

Background Art

[2] Various devices and technologies such as machine-to-machine (M2M) communication, machine type communication (MTC), smart phones and tablet PCs that require high data transfer rates It is appearing and spreading. As a result, the amount of data required to be processed in a cellular network is growing very rapidly. In order to meet such rapidly increasing data processing demands, carrier aggregation technology, cognitive radio technology, and the like to efficiently use more frequency bands, and increase the data capacity transmitted within a limited frequency Multi-antenna technology, multi-base station cooperation technology, and the like are developing.

[3] A typical wireless communication system includes a downlink (downlink, DL) band and a corresponding one of the up-link (uplink, UL) through the _band> Data transmission / perform a receive (frequency division duplex (frequency division duplex, FDD) mode, or divides a predetermined radio frame into an uplink time unit and a downlink time unit in a time domain, and performs data transmission / reception through uplink / downlink time units. (For time division duplex (TDD) mode). A base station (BS) and a user equipment (UE) transmit and receive data and / or control information scheduled in a predetermined time unit, for example, a subframe (SF). Data is transmitted and received through the data area set in the uplink / downlink subframe, and control information is transmitted and received through the control area set in the uplink / downlink subframe. To this end, various physical channels carrying radio signals are configured in uplink / downlink subframes. In contrast, the carrier aggregation technique combines a plurality of uplink / downlink frequency blocks to use a wider frequency band. By using bandwidth, a larger amount of signals can be processed simultaneously compared to when a single carrier is used.

On the other hand, the communication environment is evolving in the direction of increasing the density of nodes that user equipment can access from the periphery. A node is a fixed point capable of transmitting / receiving a radio signal with a user device having one or more antennas. A communication system with a high density of nodes can provide higher performance communication services to user equipment by cooperation between nodes.

[Detailed Description of the Invention]

[Technical problem]

As the density of nodes increases and / or the density of user devices increases, a method for efficiently using high density nodes or high density user devices for communication is required.

[6] In addition, the use of frequency bands that have not been used in the past has been discussed with the development of the technology. Since the newly introduced frequency bands have different characteristics from the existing frequency bands, it is difficult to apply the existing frame structure as it is. Therefore, the introduction of a new frame structure is required.

[7] The technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems which are not mentioned above have ordinary knowledge in the technical field to which the present invention belongs from the following detailed description. Will be clearly understood to him.

Technical Solution

[8] The present invention does not maintain the (effective) subcarrier spacing for a specific frequency band having a large Doppler effect, but changes the subcarrier spacing or the effective subcarrier spacing, thereby preventing the Doppler effect. Offsets

[9] In an aspect of the present invention, in the user equipment to set a radio frame, receiving frame setting information; Changing a frame setting from a first frame setting to a second frame setting based on the frame setting information; And transmitting or receiving a signal using a frame set according to the second frame setting. W

[10] In another aspect of the present invention, there is provided a user equipment, wherein the user equipment comprises a radio frequency (RF) unit and a processor configured to control the RF unit in setting up a radio frame. The processor may enable the RF unit to receive frame setting information. The processor may be configured to change the frame setting from the first frame setting to the second frame setting based on the frame ^' setting information. The processor may cause the RF unit to transmit or receive a signal using a frame set according to the second frame setting.

[11] In another aspect of the present invention, in the base station configures a radio frame, transmitting the frame configuration information; Change a frame setting from a first frame setting to a second frame setting according to the frame setting information; And transmitting or receiving a signal using a frame set according to the second frame setting.

In another aspect of the present invention, there is provided a base station, the base station including a radio frequency (RF) unit and a processor configured to control the RF unit in setting up a radio frame. The processor may enable the RP unit to transmit frame setting information. The processor may be configured to change the frame setting from the first frame setting to the second frame setting based on the frame setting information. The RF unit may transmit or receive a signal by using a frame set according to the second frame setting.

[13] In each aspect of the present invention, in the case where the frame setting is changed, the number of subcarriers in the non-zero power subcarrier spacing among a plurality of subcarriers in a frequency domain is equal to 'Μ according to the first frame setting. It may be changed from + Γ to W ₂ + l 'according to the second frame setting. Here, and N ₂ may be a nonnegative integer indicating the number of consecutive zero power subcarriers set between two non-zero power subcarriers according to the first frame setting and the second frame setting, respectively.

[14] In each aspect of the present invention, the random subcarrier spacing Δ / ₂ set according to the second frame setting is a subcarrier spacing Δ _! May be the same as In each aspect of the present invention, the sampling frequency / _s2 of the frame set according to the second frame setting may be the same as the sampling frequency _{/ 51} according to the first frame setting.

[16] In each aspect of the present invention, the sampling time of the frame set in accordance with the setting of the frame 2; _{, 2} may be equal to the sampling time 7, according to the first frame setting.

In each aspect of the present invention, the frame setting information may be restricted to be applied to a resource region allocated to a specific user equipment among specific frequency bands.

In each aspect of the present invention, the frame setting information may be applied to the entire system bandwidth of a specific frequency band.

In each aspect of the present invention, the frame setting information may be applied to a high frequency band exceeding a predetermined criterion.

In each aspect of the present invention, the frame setting information may be applied to a fast moving user equipment having a predetermined speed or more.

The above technical solutions are only some of the embodiments of the present invention, and various embodiments in which the technical features of the present invention are reflected will be described in detail by those skilled in the art. Based on the description, it can be derived and understood.

Advantageous Effects

According to the present invention, efficient signal transmission / reception can be performed in a frequency band newly introduced for use. This increases the overall throughput of the wireless communication system.

[23] The effects according to the present invention are not limited to the above-mentioned effects, and other effects not mentioned above are clearly apparent to those skilled in the art from the following detailed description. It can be understood. [Brief Description of Drawings]

The accompanying drawings, which are included as part of the detailed description to help understand the present invention, provide an embodiment of the present invention and together with the detailed description, describe the technical idea of the present invention. 1 illustrates a distributed antenna system (DAS), which is a kind of multi-node system.

FIG. 2 is a diagram for describing a concept of a BTS (Base Transceiver System) hotel of a multi-node system.

3 illustrates a symbol structure used in a Long Term Evolution (LTE) system.

4 is a diagram illustrating the concept of a small cell.

5 and 6 illustrate a frame design according to an embodiment of the present invention.

FIG. 7 illustrates a stop-and-wait (SAW) HARQ process according to an embodiment of the present invention.

8 illustrates a SAW HARQ process according to another embodiment of the present invention.

9 illustrates a SAW HARQ process according to another embodiment of the present invention.

[33]

10 and 11 illustrate an example of operating a flexible frame according to an embodiment of the present invention.

12 illustrates an example of a flexible frame structure according to an embodiment of the present invention.

FIG. 13 illustrates another example of a flexible frame structure according to an embodiment of the present invention. FIG.

14 and 15 are diagrams for explaining an example of a flexible frame operation according to another embodiment of the present invention.

16 illustrates an example of a flexible frame structure according to another embodiment of the present invention.

17 shows another example of a flexible frame structure according to another embodiment of the present invention.

FIG. 18 is a block diagram illustrating components of a transmitter 10 and a receiver 20 for implementing the present invention.

[Mode for Implementation of the Invention]: Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to describe exemplary embodiments of the present invention, and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, one of ordinary skill in the art appreciates that the present invention may be practiced without these specific details.

In some cases, well-known structures and devices may be omitted or shown in block diagram form centering on the core functions of the structures and devices in order to avoid obscuring the concepts of the present invention. In addition, the same components throughout the present specification will be described using the same reference numerals.

The techniques, devices and systems described below can be applied to various wireless multiple access systems. Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA), one system, orthogonal frequency division multiple access (OFDMA) systems, and SC-FDMA (SC-FDMA). Single carrier frequency division multiple access (MCD) systems and MC-FDMA (multi carrier frequency division multiple access) systems. CDMA may be implemented in a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented in wireless technologies such as Global System for Mobile Communication (GSM), General Packet Radio Service (GPRS), Enhanced Data Rates for GSM Evolution (EDGE) (ie, GERAN), and the like. OFDMA may be implemented in wireless technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.1 1 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802-20, evolved-UTRA (E-UTRA), and the like. UTRA is part of Universal Mobile Telecommunication System (UMTS), and 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of E-UMTS using E-UTRA. 3 GPP LTE employs OFDMA in downlink (DL) and SC-FDMA in uplink (UL). LTE-advanced (LTE-A) is an evolution of 3GPP LTE. For convenience of explanation, hereinafter, it will be described on the assumption that the present invention is applied to 3GPP LTE / LTE-A. However, the technical features of the present invention are not limited thereto. For example, in the following detailed description, the mobile communication system is applied to a 3GPP LTE / LTE-A system. Although described on the basis of the corresponding mobile communication system, it is applicable to any other mobile communication system except for those specific to 3GPP LTE / LTE-A.

For example, in the present invention, as in the 3GPP LTE / LTE-A system, an eNB allocates a downlink / uplink time / frequency resource to a UE, and the UE receives a downlink signal according to the eNB's allocation and uplinks. It can be applied to contention-based communication such as Wi-Fi as well as non-contention based communication that transmits link signals. The non-competitive communication method is a contention based communication method in which an access point (AP) or a control node controlling the access point allocates resources for communication between a UE and the AP. Is occupied by communication resources through competition between multiple UEs trying to access an AP. A brief description of contention-based communication techniques is a type of contention-based communication, called carrier sense multiple access (CSMA), in which a node or communication device shares a frequency band. Probabilistic media access control (MAC) to ensure no other traffic on the same shared transmission medium before transmitting traffic on a shared transmission medium (also known as a shared channel) Refers to the protocol. In CSMA, the transmitting device determines if another transmission is in progress before attempting to send traffic to the receiving device. In other words, the transmission device attempts to detect the presence of a carrier from another transmission device before attempting transmission. When the carrier is detected, the transmission device waits for transmission to be completed by another transmission device in progress before initiating its transmission. After all, CSMA is a communication technique based on the principle of "sense before transmit" or "listen before talk". Carrier Sense Multiple Access with Collision Detection (CSMA / CD) and / or Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) as a technique for avoiding stratification between transmission devices in a competitive communication system using CSMA. Is used. CSMA / CD is a stratification detection method in wired LAN environment. First, check whether PC (personal computer) or server that wants to communicate in the ethernet environment is communicating on the network and then other devices. Waits before sending data on the network before sending data. That is, when two or more users (eg, PCs, UEs, etc.) simultaneously load data, a collision occurs between the simultaneous transmissions, and the CSMA / CD monitors the collisions to allow flexible data transmission. It is a technique to help. A transmission device using CSMA / CD detects data transmission by another transmission device and adjusts its own data transmission using specific rules. CSMA / CA is a medium access control protocol specified in the IEEE 802.11 standard. WLAN systems according to the IEEE 802.11 standard do not use the CSMA / CD used in the IEEE 802.3 standard, but use a CA, that is, a collision avoidance method. Transmitting devices always detect the carrier of the network, and when the network is empty, wait for a certain amount of time according to their location on the list before sending data. Several methods are used to prioritize and reconfigure transmission devices within the list. In systems in accordance with some versions of the IEEE 802.11 standard, collisions may occur, in which case a collision detection procedure is performed. Transmission devices using CSMA / CA use specific rules to avoid stratification between data transmissions by other transmission devices and their own.

In the present invention, a user equipment (UE) may be fixed or mobile, and various devices for transmitting and receiving user data and / or various control information by communicating with a base station (BS) Flags belong to this. The UE is a terminal equipment, a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, a personal digital assistant (PDA), a wireless modem. It may be called a modem, a handheld device, or the like. In addition, in the present invention, a BS generally refers to a fixed station communicating with the UE and / or another BS, and communicates with the UE and another BS to exchange various data and control information. The BS may be referred to in other terms such as ABS (Advanced Base Station), NB (Node-B), eNB (evolved-NodeB), BTS (Base Transceiver System), Access Point (Access Point), and Processing Server (PS). In the following description of the present invention, BS is collectively referred to as eNB.

In the present invention, a node refers to a fixed point capable of transmitting / receiving a radio signal by communicating with a UE. In a particular wireless communication standard, a UE is also called a node or a point _. The term node is used in contrast to the UE. A node may be referred to as an access point or an access node in view of a point of access by a UE rather than a UE.

[47] Various types of eNBs may be used as nodes regardless of their names. For example, BS, NB, eNB, pico-cell eNB (PeNB), home eNB (HeNB), relay, repeater, etc. It can be a node. Also, the node may not be an eNB. For example, it may be a radio remote head (RRH), a radio remote unit (RRU). The RRH, RRU, etc. generally have a power level lower than the power level of the eNB. Since RRH or RRU (hereinafter, RRH / RRU) is generally connected to an eNB by a dedicated line such as an optical cable, it is generally compared with RRH / RRU compared to cooperative communication by eNBs connected by a wireless line. Cooperative communication by the eNB can be performed smoothly. At least one antenna is installed at one node. The antenna may mean a physical antenna or may mean an antenna port, a virtual antenna, or an antenna group. Nodes are also called points. In a multi-node system, the same cell identifier (ID) or different cell ID may be used for signal transmission / reception to / from a plurality of nodes. When a plurality of nodes have the same cell ID, each of the plurality of nodes behaves like some antenna group of one cell. If nodes in a multi-node system have different cell IDs, then this multi-node system is considered a multi-cell (e.g., macro-cell / femto-cell / pico-cell) system. Can be. When the multiple cells formed by each of the plurality of nodes are configured to be overlayed according to the coverage, the network formed by the multiple cells is particularly called a multi-tier network. The cell ID of the RRH / RRU and the cell ID of the eNB may be identical or different. When the RRH / RRU and the eNB use different cell IDs, both the RRH / RRU and the eNB operate as independent base stations.

In a multiple node system, one or more eNB blacks connected to a plurality of nodes may control the plurality of nodes such that an eNB controller transmits or receives signals simultaneously to a UE through some or all of the plurality of nodes. Can be. Although there are differences between multi-node systems depending on the identity of each node, the type of implementation of each node, etc., in that a plurality of nodes together participate in providing communication services to the UE on a given time-frequency resource, These multi-node systems are different from single node systems (eg CAS, conventional MIMO systems, conventional relay systems, conventional repeater systems, etc.). Accordingly, embodiments of the present invention regarding a method for performing data cooperative transmission using some or all of a plurality of nodes may be applied to various kinds of multi-node systems. For example, although a node generally refers to an antenna group spaced apart from another node by a predetermined distance or more, the node of the present invention described below Embodiments can also be applied when a node means any antenna group regardless of spacing. For example, in case of an eNB having a cross polarized (X-pol) antenna, the eNB controls a node configured as an H-pol antenna and a node configured as a V-pol antenna. Can be applied.

[49] Transmit / receive a signal through a plurality of transmit (Tx) / receive (Rx) nodes, transmit / receive a signal through at least one node selected from a plurality of transmit / receive nodes, or downlink signal A communication scheme capable of differentiating a node transmitting an uplink signal from a node receiving an uplink signal is called multiple-eNB MIMO or CoMP (Coordinated Multi-Point transmission / reception). Cooperative transmission schemes among such cooperative communication between nodes can be largely classified into joint processing (JP) and scheduling coordination. The former may be divided into joint transmission (JT) / JR oint reception and dynamic point selection (DPS), and the latter may be divided into coordinated scheduling (CS) and coordinated beamforming (CB). DPS is also called dynamic cell selection (DCS). Compared to other cooperative communication techniques, more diverse communication environments can be formed when JP among cooperative communication techniques is performed. JT in JP refers to a communication scheme in which a plurality of nodes transmit the same stream to the UE, and JR refers to a communication scheme in which a plurality of nodes receive the same stream from the UE. The UE / eNB synthesizes signals received from the plurality of nodes to recover the stream. In the case of JT / JR, since the same stream is transmitted from / to a plurality of nodes, reliability of signal transmission may be improved by transmit diversity. JP enhancement DPS refers to a communication technique in which a signal is transmitted / received through one node selected according to a specific rule among a plurality of nodes. In the case of DPS, since a node having a good channel state between the UE and the node will be selected as a communication node, the reliability of signal transmission can be improved.

[50] FIG. 1 illustrates a distributed antenna system (DAS), which is a kind of multi node system.

Referring to FIG. 1, a DAS is composed of an eNB and antenna nodes connected to the eNB. An antenna node may also be referred to as an antenna group, an antenna cluster, or the like. The antenna node is connected to the eNB by wire or wirelessly and may include one or several antennas. In general, antennas belonging to one antenna node have a distance of several meters between the nearest antennas. It has the characteristic that it belongs to the same spot locally, and the antenna node acts like an antenna point to which the UE can connect.

[52] Unlike a centralized antenna system (CAS) in which antennas of an eNB are concentrated in a cell center, a DAS has antennas managed by one eNB spread at various locations in a cell. A DAS is distinguished from a pico cell in that femto cell blacks are distinguished in that multiple antenna nodes make up a cell, which is difficult to locate at a point as they are spaced apart from each other over a certain interval. Initially, DAS was used to repeat the same signal by installing more antennas to cover the shadow area. However, in large scale, the DAS is used by antennas of eNBs to send or receive multiple data streams simultaneously. Similar to a multiple input multiple output MIMO system in that it can support a UE or multiple UEs, while conventional MIMO technology allows antennas concentrated at one point of the eNB to participate in communication with the UE, while the DAS At least one of the distributed nodes of participates in communication with the UE. As a result, the DAS can achieve high power efficiency, low channel correlation due to correlation and interference between low-eNB antennas, and low-frequency distance between the UE and the antenna, compared to the CAS. Regardless of the location, there is an advantage that communication performance of relatively uniform quality is secured.

In the present invention, a cell refers to a certain geographic area where one or more nodes provide a communication service. Therefore, in the present invention, communication with a specific cell may mean communication with an eNB or a node providing a communication service to the specific cell. In addition, the downlink / uplink signal of a specific cell means a downlink / uplink signal to / from an eNB or a node that provides a communication service to the specific cell. The cell providing the uplink / downlink communication service to the UE is particularly called a serving cell. In addition, the channel state / quality of a specific cell refers to the channel state / quality of a channel or communication link formed between an eNB or a node providing a communication service to the specific cell and a UE. In an LTE / LTE-A based system, a UE transmits a downlink channel state from a particular node on a Cell-specific Reference Signal (CRS) resource to which the antenna port (s) of the particular node are assigned to the particular node. Measurement may be performed using CSI (RS) and / or CSI-RS (s) transmitted on a channel state information reference signal (CSI-RS) resource. Meanwhile, the 3GPP LTE / LTE-A system The concept of cell is used to manage radio resources. Cells associated with radio resources are distinguished from cells in geographic area.

A general wireless communication system performs data transmission or reception through one DL band and one corresponding UL band (in frequency division duplex (FDD) mode), or a predetermined wireless frame ( A radio frame is divided into an uplink time unit and a downlink time unit in a time domain, and data transmission or reception is performed through an uplink / downlink time unit (time division duplex (TDD) mode). If). However, in recent wireless communication systems, a carrier aggregation or bandwidth aggregation technique using a larger UL / DL bandwidth is collected by using a plurality of UL and / or DL frequency blocks to use a wider frequency band. Is being discussed. Carrier aggregation (CA) performs DL or UL communication using a plurality of carrier frequencies, and performs DL or UL communication by putting a fundamental frequency band divided into a plurality of orthogonal subcarriers on one carrier frequency. It is distinguished from an orthogonal frequency division multiplexing (OFDM) system. Hereinafter, each carrier aggregated by carrier aggregation is called a component carrier (CC). For example, three 20 MHz CCs may be gathered in the UL and the DL to support a 60 MHz bandwidth. Each CC may be adjacent or non-adjacent to each other in the frequency domain. The bandwidth of the UL CC and the bandwidth of the DL CC may be the same, but the bandwidth of each CC may be determined independently. In addition, asymmetrical carrier aggregation in which the number of UL CCs and the number of DL CCs are different is also possible. A DI7UL CC limited to a specific UE may be referred to as a configured serving UL / DL CC at a specific UE. The 3GPP LTE-A standard uses the concept of "cell" for the management of radio resources. A "cell" associated with a radio resource is defined by a combination of DL resources and UL resources. A "cell" of radio resources may be configured as a DL resource alone, or a combination of DL and UL resources, or a combination of UL resources alone. The linkage between the carrier frequency of the DL resource and the carrier frequency of the UL resource may be indicated by system information. For example, a combination of a DL resource and a UL resource may be indicated by a System Information Block Type 2 (SIB2) linkage. Here, the carrier frequency means a center frequency of each cell or CC. Primary frequency A cell operating on the primary cell is called a primary cell (PCell) or PCC, and a wexel operating on the secondary frequency (secondary frequency) is called a secondary cell (SCell) or SCC. The carrier corresponding to the PCell in downlink is called a DL primary CC (DL PCC), and the carrier corresponding to the PCell in the uplink is called a UL primary CC (DL PCC). SCell means a cell that can be configured and used to provide additional radio resources after RRC (Radio Resource Control) connection establishment is made. Depending on the capabilities of the UE, the SCell may, together with the PCell, form a set of serving cells for the UE. The carrier corresponding to the SCell in downlink is called DL secondary CC (DL SCC), and the carrier corresponding to the SCell in uplink is called UL secondary CC (UL SCC). RRC—In case of UE that is in CONNECTED state but carrier aggregation is not configured or carrier aggregation is not supported, there is only one serving cell configured only for PCell.

[55] In summary, a "cell" in a geographic area may be understood as a coverage in which a node can provide a service using a carrier, and a "sal" of a radio resource is configured by the carrier. It is associated with bandwidth (BW), which is the frequency range being. Since the downlink coverage, which is a range in which a node can transmit a signal of a valid strength, and the uplink coverage, which is a range in which a signal of a valid strength can be received from a UE, depends on the distance that a carrier carrying the signal arrives. The coverage of a node is also associated with the coverage of the "cell" of radio resources used by that node. Thus, the term "cell" can sometimes be used to mean the coverage of a service by a node, sometimes a radio resource, and sometimes a signal using the radio resource to reach an effective strength.

FIG. 2 is a diagram for explaining the concept of a BTS (Base Transceiver System) hotel of a multi-node system. In particular, FIG. 2 (a) shows a traditional Radio Access Network (RAN) architecture, and FIG. 2 (b) shows a small cell RAN framework with a BTS hotel and a DAS. It is shown. The concept of small cells is described in more detail in FIG. 4.

Referring to FIG. 2 (a), in the conventional celller system, one TS manages three sectors and each eNB performs a base station controller (RNC) / RNC through a backbone network. It is connected to (Radio Network Controller). However, in a multi-node system such as DAS, eNBs connected to each antenna node are located in one place (BTS hotel). I can collect it. This can reduce the cost of land and buildings to install the _eN B, and the maintenance and management of the eNB can be easily performed in one place. In addition, by installing both the BTS and MSC (Mobile Switching Center) / BSC / RNC in one place, the backhaul capacity can be increased.

FIG. 3 illustrates a symbol structure used in a Long Term Evolution (LTE) system.

A duration of a radio frame used in the existing LTE / LTE-A system is 10 ms (307200 _s ), and one radio frame has 10 equally sized subframes (subframe, SF). It is composed of Numbers may be assigned to ten subframes in one radio frame. Here, T _s represents a sampling time and is represented by r _s = l / (2048 * 15 kHz). The length r _subframe of each _subframe is 1ms and one _subframe consists of two slots. Thus, one radio frame consists of 20 slots, each slot having a length of 7 _sl0t of ₁₅₃₆₀ _S = 0.5 ms. Twenty slots in one radio frame may be sequentially numbered from 0 to 19. The time for transmitting one subframe is defined as a transmission time interval (TTI). The time resource may be distinguished by a radio frame number (also called a radio frame index), a subframe number (black is also called a subframe number), a slot number (or slot index), and the like.

The existing LTE / LTE-A system supports two types of frame structures according to the length of a cyclic prefix (CP) as shown in FIG. 3. Referring to FIG. 3 (a), one slot includes seven OFDM symbols in the case of a normal CP, and one slot includes six OFDM symbols in the case of an extended CP. For reference, an OFDM symbol may be called an OFDM symbol or SC-FDM (Single Carrier-Frequency Division Multiplexing) according to a multiple access scheme. Since SC-FDMA can be viewed as a specific form of OFDMA, the term "symbol" or "OFDMA symbol" is used in the present invention to refer to an OFDM symbol and an SC-FDM symbol.

3, the length T _CP of the normal CP is 160 _S -5.1 s for the first OFDM symbol of the subframe and 160 _S 4.7 / s for the remaining OFDM symbols. In FIG. 3, the length of the extended CP: ^ is 512 _S -16.1 s. In FIG. 3, T _u denotes an effective OFDM symbol period, and means a corresponding time of the inverse of the subcarrier interval. [62] The reason why the LTE / LTE-A system supports two CPs is that the LTE system supports various scenarios of the cellar system. In fact, the LTE system covers the environment in the indoor (urban), urban (suburban), rural (rural), and supports the movement speed of the UE up to 350 ~ 500km.

[64] The center frequency of LTE / LTE-A system is generally 400MHz to 4GHz, and the available frequency band is 1.4 to 20MHz. This means that delay spread and Doppler's frequency differ from each other according to the center frequency and the available frequency band. In case of the normal CP, subcarrier spacing Af = 15kHz, the length of the CP is about 4.7 / s, and in the case of the extended CP, the subcarrier spacing is the same as the normal CP and the length of the CP is about 16.7 / s. In the LTE system, the subcarrier spacing is predetermined, and the subcarrier spacing corresponds to the sampling frequency divided by the FFT size. In the LTE system, a sampling frequency of 30.72 MHz is used, and subcarrier spacing A / = 15 kHz can be obtained by dividing 3 (). 72 MHz by 2048, the FFT size used in the LTE system.

An extended CP may be used for a suburban cell or a rural cell, which is relatively large due to a long CP duration. In general, since the delay spread is longer in a suburban cell or a rural cell, an extended CP having a relatively long length is required to reliably solve inter symbol interference (ISI). However, in case of the extended CP, the CP overhead is increased relative to the normal CP, so that the increase in the CP length causes a loss in spectral efficiency and / or transmission resource. off) is present. In conclusion, in the LTE / LTE-A system, the lengths of the normal CP and the extended CP are determined to support various deployment scenarios in which cells are deployed indoors, cities, suburbs, and rural areas. The following design criterion was used to make the decision.

[65] [Equation 1]

T _CP ≥T _d

[66] [Equation 2]

[67] [Equation 3] T _CP Af «\

In Equations 1 to 3, T _CP denotes a length of CP, / _dmax denotes a (maximum) Doppler frequency, and Δ / denotes a subcarrier spacing. In Equation 1, T _d represents the maximum excess delay or the maximum channel delay: The last channel tap given a power delay profile (PDF) called a channel delay profile. The delay time of tap). For example, the delay and power of tap # 0 (relative power) are 10ns and OdB, respectively, and the delay and power of tap # 1 are 20ns and -5 dB, respectively, and the delay and power of tap #N (relative power). Given a PDF with 500 ns and -20 dB, respectively: T _d = 500 ns.

Equation 1 is a criterion for preventing ISI, Equation 2 is a criterion for sufficiently maintaining inter cell interference (ICI) according to Doppler, and Equation 3 is spectral It is a standard for spectral efficiency.

In the future, the LTE system is considering introducing a local area. In other words, in order to further strengthen service support for each UE, the introduction of a new cell deployment having a concept of local area access is being considered. This local area is called a small cell.

FIG. 4 is a diagram illustrating the concept of a small cell.

[72] Referring to FIG. 4, a system bandwidth wider than a system bandwidth of an existing LTE system is configured for a cell having a higher center frequency than a band having a center frequency operated in an existing LTE system. Can be By using small cells, existing cell bands support basic cell coverage based on control signals such as system information. Can be maximized. Therefore, local area access can be used for low-to-medium mobility (jEs) at low speeds located in narrower areas, and for small cells of 100m smaller than conventional cells where the distance between the UE and eNB is in km Can be used for communication.

In such small cells, the following channel characteristics are expected as the distance between the UE and the node is short and the high frequency band is used.

1) Delay spread: As the distance between the eNB and the UE becomes shorter, the delay of the signal may be shortened. 2) Subcarrier Spacing: When the same OFDM-based frame structure as the LTE system is applied, an extremely larger value than the existing subcarrier spacing of 15 kHz may be set as the subcarrier spacing because the allocated frequency bandwidth is large. .

3) Doppler's frequency: Since a high frequency band is used, a higher Doppler frequency may appear than when a low frequency band is used for a UE of the same speed. Accordingly, the coherent time, which is a time duration in which the channel impulse male answer is considered unchanged in the communication system, can be extremely shortened.

Due to these characteristics of the high frequency band, when the existing frame structure is applied to the high frequency band, ISI and ICI may not be effectively prevented, and spectral efficiency may be lowered. Therefore, the present invention proposes a frame structure for high frequency band transmission.

In general, in the high frequency band where the center frequency / _c is 5 GHz or more, the delay spread of the channel tends to be short, and the path loss of the channel increases greatly in the high frequency band, and the stable performance is obtained as the distance from the base station increases. I can guarantee it. Therefore, in the future, communication using a high frequency band is expected to introduce a narrower cell structure than conventional cell communication. Due to the ease of resource utilization and control, OFDM, which is a multiple access technique, is also expected to be used in the same way.

[79] OFDM Symbol Definition for High Frequency Frame

In the present invention, system parameters for high frequency band transmission are determined as shown in the following table. Table 1 shows OFDM-based system parameters for high frequency band transmission.

[81] [Table 1]

In generating an OFDM symbol, a CP must be inserted in the first half of an OFDM symbol (also called an OFDMA symbol) to prevent ISI. As described above, the CP duration of the current LTE system is set to 4.7; ^ for a regular CP and 16.7 / s for an extended CP. These CP values used in the current LTE system is a value that reflects the power delay profile (power delay profile) that occurs when assuming a fairly wide cell. However, in consideration of the characteristics of the high frequency band and the small cell where delay spread is expected to be relatively short, it is not necessary to maintain such a long CP period. Therefore, it is possible to set and operate an extremely short CP for a high frequency band and a small cell. Decreasing the CP length leads to an increase in transmission resources, which may result in an increase in spectral efficiency. However, dramatically reducing the length of all CPs can act as a critical factor for timing synchronization. In an LTE system, a UE generally obtains initial timing through cell search and synchronization procedures. In this case, CP correlation or reference signal correlation is used. Sometimes used at the same time. Therefore, it may be difficult to obtain accurate timing synchronization when the CP period used to calculate correlation is extremely short. Also, in actual implementation, since the CP period is used as an important tool for implementing a modem by measuring a frequency offset through correlation, a minimum CP period guarantee is required. For this reason, a relatively long CP period should always be included on the frame structure. In the present invention, the CP length of the UE is determined to be 0.5 us or more, reflecting the channel characteristics of the high frequency band.

On the other hand, the high frequency band has a characteristic that the root mean square (RMS) delay spread is shortened and the coherent bandwidth is increased. Since this characteristic leads to a widening of a frequency band considered to be the same channel, a value larger than the subcarrier spacing of the existing LTE and Cellular systems can be used as the subcarrier spacing for the high frequency band. In the present invention, the following consideration factors and design criteria are used to determine the subcarrier spacing for the high frequency band.

[84] [Table 2]

The subcarrier spacing should be determined to a size that can sufficiently reflect the Doppler frequency due to the movement of the UE. In the present invention, the design criteria are given as follows.

[86] [Equation 4]

(-) xf _c / Af = K (where K «1),

c

Af = (v * f _c ) / (c * K)

The subcarrier spacing is determined by applying the values of the maximum Doppler frequencies of Table 2 to Equation 4. For example, in equation 4, the UE speed v is 250 km / h, c = 3 * 10 ⁸ m / s, the center frequency ^ is applicable to 30GHz. If K is set to 1/15, which is significantly smaller than 1, the final subcarrier spacing ᅀ / becomes 104.25 kHz. Here, K may be changed according to the center frequency, delay profile, UE speed, and Doppler frequency at which the frame is designed.

Based on the CP and subcarrier spacing determined as described above, the OFDM symbol length, the OFDM symbol duration, the overhead in terms of energy, and the energy efficiency efficiency in terms of energy) are determined.

[89] Meanwhile, the size of the basic system bandwidth of the high frequency band is set based on the system band of 500 MHz or more. Table 1 shows the FFT size (FFT derived when the size of the basic band is set to 500 MHz. size, OFDM sampling frequency (O'FDM sampling frequency), available subcarriers, occupied BW (Occupied BW), guard-band, and total system BW are determined. It was. When the default band is set to 500 MHz or more, the values can be changed.

[90] <| TTI-Based Design for High Frequency Frames>

In the present invention, the following frame design method is proposed in consideration of various implementation issues and design environments of the UE.

[92] * first line: memory size limitation

[93] * Option 2: UE Processing Timeout (keeping the number of 8 Hybrid Automatic Retransmission reQuest (HARQ) processes)

[94] * Third proposal: UE processing timeout (increasing the number of HARQ processes)

[95] The design method according to each item is explained in detail as follows.

[96] 1. Frame Design Method

[98] (1) Design Condition: Approach Memory Size (Soft Buffer Size Limit)

(2) Assumptions: It is assumed as a single codeword (SCW), and the number of HARQ processes (number of HARQ processes) is maintained at the same eight as the existing LTE system. Here, the soft buffer size (or memory size) is It is constrained by the maximum soft buffer size of LTE. Table 3 shows the maximum size of encoded bits based on the maximum soft buffer size of LTE (see 3GPP LTE 36.213).

[100] [Table 3]

In addition, the service coverage of the system is assumed to be 1 km or less, and the round trip delay (RTT) is assumed to be 6.67 / s. Therefore, the processing time of the UE is finally determined as follows.

[102] [Equation 5]

UE processing time = 3xTTI-RTT

For example, the UE processing time may be determined as 3 X TTI (0.222us)-RTT _lkm (6.67 / s) = 0.659.

(3) Decision Content: Referring to Table 4 showing the definition of Τ 안의 in the first, one TTI is determined to be 222 js, which is a period corresponding to the last 22 OFDM symbols. The time axis frame structure and the resource lattice according to the first may be shown as shown in FIGS. 5 and 6, respectively. In the present invention, the resource grid is defined by the TTI in the time domain by the subcarriers available in the frequency domain. Referring to Table 1 is the number N _ac = 40% of the resources used within the ^"grid subcarriers when the base system BW 500MHz. According to ^ 1, a resource grid is represented by 4096 subcarriers and 22 OFDM symbols. A smallest resource unit for downlink transmission or uplink transmission is called a resource element (RE). One RE is composed of a partial carrier and one OFDM symbol. In other words, each element in the resource grid is called a resource element, and the resource element in each resource grid may be uniquely defined by an index pair k,). Where k is an index given from 0 to 'N _ac -1, in the frequency domain, and / is an index given from 0 to w _sym -r in the time domain.

[105] [Table 4]

The eight processes based HARQ according to the first term are determined as shown in FIG. 7. FIG. 7 illustrates a stop-and-wait (SAW) HARQ process according to one embodiment (first embodiment) of the present invention. Referring to FIG. 7, data transmission transmitted by the eNB in TTI # 0 is received in TTI # 0 after propagation delay. The UE attempts to decode the data transmission and transmits an acknowledgment / negative acknowledgment (A / N) transmission for the data transmission in TTI # 4, which is 4 TTIs later. The acknowledgment / false reception is received by the eNB in TTI # 4 after propagation delay. Since the four TTIs are much larger than 0.659 s, which is the processing time determined according to the first, '3TTI-RTT', the UE can effectively transmit a signal for A / N transmission. The eNB may know whether the UE has successfully received the data transmission transmitted in TTI # 0 based on the A / N transmission, and if the UE successfully receives, 4 TTIs have passed from TTI # 4. Starting from TTI # 8, new data transmission or data retransmission can be performed. Meanwhile, Table 5 shows the maximum transmission block (TB) size definition according to the first clause.

[108] [Table 5]

[109] 2. The second frame design method

[1] Design Conditions: Medium Access Control (MAC) / Physical (PHY) Process Restriction (UE Processing Time)

[111] (2) Assumptions: Assume SCW and keep the number of HARQ processes equal to 8 as in the existing LTE system. As in the first proposal, the service coverage of the system is assumed to be less than 1 km and the RTT is assumed to be 6.67 // s. However, the second proposal assumes that the processing time of the UE is 2.3 ms.

(3) Decision Content: The TTI is determined to be 767.6 s, which is a period corresponding to the last 76 OFDM symbols. 8 illustrates a SAW HARQ process according to another embodiment (second embodiment) of the present invention. 8 process-based HARQ in the second is determined as shown in FIG. In FIG. 8, one ΤΉ is 767 / s. Therefore, the final TB size is also required to be increased by about 3.45 times compared to the existing LTE system.

[113] 3. The third frame design method

[114] (1) Design condition: MAC / PHY process limit (increased HARQ processes)

(2) Assumptions: It is assumed to be SCW. The service coverage of the system is assumed to be less than 1 km, so that the RTT is 6.67 s 7}. However, it is assumed here that the processing time of the UE is 2.3ms, and one TTI is assumed to be 222 / zs, which is a period for 22 OFDM symbols. [116J (3) Decisions: ΓΠ is 121, the last 22 OFDM symbols, which is the same as the first proposal. However, as shown in FIG. 9, the number of HARQ processes increases to 24. 9 illustrates a SAW HARQ process according to another embodiment (third proposal) of the present invention.

[117] The OFDM-based high frequency frame arbitrary parameters determined according to the first to third items described above are summarized as follows.

[118] [Table 6]

[119J <Flexible Frame Structure>

The present invention proposes to operate a flexible frame in consideration of the Doppler effect of a UE or a link. Hereinafter, flexible frame operation methods will be described with reference to FIGS. 10 to 17. In the following proposals, a frame according to the aforementioned frame design is included. r \ j \! \ \ \ I \} \) Ό ^ d Structures may be used. The eNB may set an appropriate frame type or subframe type according to the state of the UE (s) or link in consideration of the Doppler effect. When the frame setting is changed, the subframe or TTI in the frame is also changed according to the changed frame setting. UE (s) or connected UE (s) wishing to access an eNB may be configured based on link configuration information or frame configuration information transmitted by an eNB through a higher layer (eg, MAC layer or RRC layer) signal. Frame (s) or subframe (s) can be configured for communication with the system. The link setting information or the frame setting information according to the present invention may be information indicating a change in the frame structure type according to any one of the embodiments of the present invention described later. The information indicating the change of the frame structure type may be information indicating any one of a plurality of predefined frame structures, and a parameter that may mean a change of the frame structure according to any one of the embodiments of the present invention. (S) may be, for example, information indicating a (effective) subcarrier spacing, a sampling time, a number of samples, a number of OFDM symbols, and / or a change in the FFT size.

The embodiments described with reference to Tables 1 to 6 can be used in any one of the frame structures applied to the flexible frame below. For example, the CP length, the subcarrier spacing, the number of OFDM symbols per ΤΉ, the TTI length, and the like, determined according to any one of the above-described embodiments of the present invention, are used in any of the plurality of frame structures utilized in the flexible frame of the present invention. Can be used as one.

As described above, the center frequency increases in the ί frequency band. The maximum Doppler frequency / d, max is defined by the following equation.

[123] [Equation 6] = ~ ^X fc

c

Referring to Equation 6, it can be seen that as the center frequency f _c increases, the Doppler frequency / _{d, max} also increases. Increasing the Doppler frequency destroys orthogonality between subcarriers in the frequency domain, increasing the probability of system degradation. Doppler frequency can be reduced by increasing the subcarrier spacing in OFDM-based subframe designs. However, increasing the subcarrier spacing shortens the symbol period in the time domain, which leads to system loss because more reference signals for channel estimation are required in the time domain. Conversely, in the time domain Increasing the symbol period decreases the subcarrier spacing in the frequency domain, thereby destroying the orthogonality between subcarriers due to the Doppler frequency. However, since the frame structure in the system design cannot be changed frequently once determined, there is no flexibility and it is always designed to accept only minimal changes. Accordingly, the present invention proposes a flexible frame operation method for overcoming the Doppler frequency in a high frequency band transmission environment in which the channel state can be extremely changed according to the moving speed of the UE.

For reference, hereinafter, a frame structure for a link or UE (s) having a low Doppler effect will be referred to as a frame structure type -A, and a frame structure for a link or UE (s) having a high Doppler effect will be referred to as a frame structure type- As B, flexible frame operating embodiments of the present invention are described. Hereinafter, embodiments of the present invention will be described assuming that two frame structure types are defined according to the Doppler frequency, but more than two frame structure types may be defined according to the influence of the Doppler frequency.

In operation of the flexible frame described below, it may be predetermined that any one of a plurality of frame structure types is used at initial connection. For example, when a UE attempts to access an eNB, it may assume that a frame is set according to a predetermined frame structure, that is, frame setting, and attempt to access. If the connection attempt according to the predetermined frame structure fails, the UE may try to connect again using another frame structure. In the present invention, the (effective) subcarrier spacing may be determined according to the frame structure. That is, if the (effective) subcarrier spacing and the like are different, they may correspond to different frame structures.

[127] '■ Proposal 1) The eNB can directly change the subcarrier spacing of the frame according to the Doppler frequency change on the link. That is, in the proposal 1 of the present invention, the frame structure may be changed by changing the actual subcarrier spacing.

10 and 11 are diagrams for explaining an example of a flexible frame operation according to an embodiment of the present invention.

Referring to FIG. 10, the present invention maintains the TTI and system bandwidth, which form the basic configuration of a frame, changes the subcarrier spacing according to a link situation, and operates a frame structure suitable for the changed subcarrier spacing. [130] Flexible Switching of a Frame Structure When a High Doppler Frequency in a Cell, That is, When a Ratio of a Fast Mobile UE Is Above a Reference Value or a High Speed Backhaul Support Request Such as a High Speed Train This can be done.

In Proposal 1 of the present invention, as shown in FIG. 10, that is, the subcarrier spacing is substantially changed in the frequency region of the frame. For example, referring to FIG. 10, when the Doppler frequency increases, the present invention increases the subcarrier spacing from Δl to Δ / ₂ .

FIG. 11 is a diagram comparing the degree of influence of CFO according to subcarrier spacing when a center frequency offset (CFO) occurs due to the same Doppler frequency.

Increasing the subcarrier spacing may reduce the CFO caused by the increase in the Doppler frequency. A more detailed explanation of the principle that increasing the subcarrier spacing leads to decreasing the center frequency offset is as follows. When each subcarrier of OFDM is sampled at the point where the subcarrier index is located, the signal of the target subcarrier is accurately detected since the signals of the other subcarriers are zero-crossed. However, referring to FIG. 11 (a), as the Doppler frequency increases, the CFO also increases, making it difficult to accurately detect a signal at the zero-crossing point between subcarriers. That is, referring to FIG. 11 (a), accurate signal detection is difficult because the zero-crossing point at which the signal should be detected is not shaken at the top of the sinusoid but within the CFO range due to the Doppler frequency. For example, if the zero-crossing point is shaken at maximum, the strength of the desired signal is smaller than the strength of the side subcarrier signal acting as an interference signal for the desired signal, resulting in improved signal detection performance. It can be greatly reduced. When neighboring subcarriers act as mutual interference and it becomes difficult to distinguish subcarriers from each other, the orthogonality of subcarriers is said to be destroyed. However, as shown in FIG. 11 (b), when the subcarrier spacing increases, even if the zero-crossing point is shaken, the distance between the subcarriers may be farther away, thereby reducing orthogonal breakthrough. As a result, the influence of the frequency offset caused by the Doppler frequency for a given period is reduced through the operation of the frame structure with increased subcarrier spacing.

However, the subcarrier spacing of the frame is related to the sampling frequency / period of the time domain. Hereinafter, the proposals 1 ′ 1 and 1-1 of the present invention related to the sampling frequency / period will be described. [135] · Proposal 1-1) Only subcarrier spacing is changed to operate flexible frames, and the same sampling frequency / period is used in the time domain.

Prior to describing Proposal 1-1 of the present invention, a relationship between sampling frequency / period and subcarrier spacing will be described. Sampling frequency / _s and period 7 has an inverse relationship as shown in equation (7), and sampling frequency / _s and Δ / has a relationship as shown in equation (8).

[137] [Equation 7]

T _s = iif _s

[138] [Equation 81

f _s = AfxFFT _size = BW _max

In Equation 8, ^ denotes a system bandwidth, and FFT _Size denotes a size of a fast Fourier transform. Fr _size affects the number of subcarriers. The total transmission bandwidth can be calculated by multiplying the subcarrier spacing Δ / corresponding to the size of one subcarrier by the subcarrier number Fi _size .

According to the proposal 1-1 of the present invention, only a subcarrier spacing is changed for a flexible frame configuration, and a bandwidth and a sampling period are maintained. Since the sampling period 7 is fixed, the sampling frequency / _{s is} also fixed. In other words, when the subcarrier spacing becomes larger or smaller, the FFT becomes smaller or larger, so that the sampling frequency is maintained. For example, if the subcarrier spacing Δ / is increased by 2 times from “100 kHz to 200 kHz,” it means that the FFT size is reduced by 1/2 to “2048 → 1024”, and the OFDM symbol period of the time domain is reduced by 1/2. That is, if the subcarrier spacing is changed by a factor of two, the OFDM symbol period is reduced by 'Ι / χ' times. Therefore, twice as many OFDM symbols exist in the same ΤΤΙ in the frame structure.

Therefore, in order to operate the flexible frame according to the proposal 1-1 of the present invention, the transmitter and the receiver must each have an FFT block having a size inversely proportional to each subcarrier spacing. That is, the transmitter and the receiver should be able to provide or configure an FFT block for each subcarrier interval.

12 illustrates an example of a flexible frame structure according to an embodiment of the present invention. In particular, FIG. 12 illustrates an example of a change in the frame structure according to the proposal 1-1 of the present invention for the case where the subcarrier spacing is increased twice. _,

If the subcarrier size decreases in the FFT size, the OFDM symbol period _sym = T _CP + = FFT _slze -T _s ) ≡-decreases. Therefore, if the subcarrier spacing is increased twice, the number of OFDM symbols in the frame structure is doubled. For example, according to the proposal 1-1 of the present invention, when the carrier spacing increases from A / i = Δ / to Δ / ₂ 2 .Δ /, the frame structure is a frame structure type as shown in FIG. Can be changed from A to the frame structure type -β. Referring to FIG. 12, the subcarrier spacing is changed according to the proposal 1 of the present invention, but the sampling time of the frame structure type -A before the subcarrier spacing is changed, that is, the pream structure type after the sampling period 7 _{; 1} and the subcarrier spacing are changed. Sampling time 7 of -B; _{And 2} remain the same according to proposal 1-1 of the present invention. However, the sampling number is changed to 1 / (Δ / ₂ / Δ /,). In the case of Fig. 12, the number of samplings is enjoyed by 1/2 after the change than before the change of the subcarrier interval by 1 / (2/1).

[144J ^■ Proposal 1-1) The subcarrier spacing is changed to operate the flexible frame, and the sampling time / frequency of the time domain and the frequency domain is also changed.

13 illustrates another example of a flexible frame structure according to an embodiment of the present invention. In particular, FIG. 13 illustrates an example of a change in the frame structure according to the proposal 1-2 of the present invention for the case where the subcarrier spacing is increased by 2 times.

In the proposal 1-2 of the present invention, unlike the proposal 1-1, the subcarrier spacing and the sampling period are simultaneously changed in order to set up the flexible frame. For example, according to the proposal 1-2 of the present invention, when the subcarrier spacing increases, the sampling frequency / _s becomes large, and the sampling period T _s becomes short. However, the FFT size is maintained even if the subcarrier spacing is changed. For this reason, the FFT block of one size can be used by the transmitter and the receiver.

For example, if the subcarrier spacing ᅀ / is doubled from “100 kHz to 200 kHz”, the sampling frequency is doubled and the sampling period is 1/2 times shorter. In the proposal 1-2 of the present invention, unlike the proposal 1-1 of the present invention, the relationship of Equation 8 is changed to the relationship of the following equation.

[148] [Equation 9]

f _s ^ AfxFFT _size ≠ BW _{m & x}

If the same FFT size is applied regardless of the subcarrier spacing, it can be seen that Equation 8 changes the system bandwidth. The system bandwidth available at a particular center frequency available to the eNB or UE may vary depending on the configuration. Unlike the frame structure, since it is always the same, the changed system bandwidth cannot be applied as it is due to the change of subcarrier spacing. In other words, even if the subcarrier spacing changes, the effective system BW must be maintained. Finally, a method is needed to compensate for the difference between the effective system BW and S _max according to f _s = Afx FFT _si∞ . The present invention uses a subcarrier (mill subcarrier) to compensate for the difference between the effective system BW and 따른 according to / _s = A / x F r _size . The null subcarrier is a subcarrier whose power of the subcarrier is' 0, and is also called a zero subcarrier or a zero power subcarrier. IH: To distinguish from a null subcarrier, a subcarrier whose transmit power is not '0' is called a non-zero subcarrier or a non-zero power subcarrier. The transmitter transmits the subcarrier corresponding to the null subcarrier by setting the transmit power to '0,' and the receiver receives the signal by assuming that the transmit power of the subcarrier corresponding to the null subcarrier is '0'. Perform rate matching, decoding or demodulation.

The present invention relates to a system BW subcarrier for a band exceeding an effective system BW in order to compensate for a difference between a system BW changed according to an increase of a subcarrier spacing and a basic system BW, that is, an effective system BW. On both sides, the null subcarrier (s) are assigned to maintain the increased system bandwidth as the subcarrier spacing increases. That is, when the system _max according to the subcarrier spacing is larger than the effective system BW of the corresponding frequency band, the subcarriers corresponding to the bandwidth corresponding to the difference between the BW _max calculated according to the subcarrier spacing and the effective system BW are null subcarriers. Subcarriers farthest from the center of the frequency band of interest are set as the null subcarriers.

[151] A system BfV _max according to the subcarrier spacing and an effective system of the corresponding frequency band

If the total number of subcarriers X in bandwidth corresponding to the difference in BW is X, then if X is even, the X / 2 subcarrier (s) with the smallest subcarrier index and the largest subcarrier index

X / 2 subcarrier (s) are set to null subcarriers. For example, referring to FIG. 13, when the effective system BW is AfxFFT _size , the subcarrier spacing is 2. If increased to ᅀ /, subcarriers corresponding to each quarter region of both ends of all subcarriers based on FFT size are defined as null subcarriers. Resource allocation is not performed on the null subcarriers. If X is odd, then the ceiling (X / 2) subcarrier (s) with the largest subcarrier index and 'ceili _ng (X / 2)-Γ subcarrier (s) with the smallest subcarrier index are 'Ceiling (X / 2) ᅳ 1 with the largest subcarrier index set or null subcarrier indexes, and the' _C eiling (X / 2) 'subcarrier (s) with the smallest subcarrier index are null subcarriers. Can be set to.

On the other hand, the flexible frame operating method according to the proposal 1-2 of the present invention simultaneously changes the subcarrier spacing, the OFDM symbol period, and the sampling period 7; according to the change of the frame structure. For example, referring to FIG. 13, the subcarrier spacing is changed twice but the FFT size remains the same, so the sampling frequency is doubled. Accordingly, the OFDM symbol period T _s is 1/2 times, so that the same period (eg, The number of OFDM symbols included in the TTI is doubled.

[153] 画 Proposal 2) The eNB changes the effective subcarrier spacing without changing the subcarrier spacing of the frame according to the Doppler frequency change on the link.

Proposal 2 of the present invention proposes a method of configuring a flexible frame structure according to a change in doppler frequency without changing a basic subcarrier spacing, a symbol period, and an FFT size on a frame. Proposal 2 of the present invention, unlike the aforementioned proposal 1 of the present invention, separate frame operations may be performed for each UE. However, in order to provide robustness of Doppler overcoming of the UE, the Doppler overcoming per UE is enhanced and the transmission efficiency is reduced, so there is a trade-off relationship between the Doppler effect overcoming and transmission efficiency per UE. Briefly explaining the principle of the proposal 1-2 of the present invention.

An increase in the Doppler frequency has destroyed the orthogonality between subcarriers, which has been described above. Since proposal 2 of the present invention does not change the subcarrier spacing Δ /, the probability of causing interference between subcarriers does not change. However, proposal 2 of the present invention lowers the degree of interference between subcarriers by widening the effective subcarrier spacing by inserting null subcarriers between specific subcarriers. That is, the proposal of the present invention: 2 increases the effective subcarrier spacing by alternating non-zero power subcarriers and N (≥0) consecutive zero power subcarrier (s) along the frequency axis (ie in the frequency domain). Shout. That is, in proposal 2 of the present invention, non-zero power subcarriers are set for every NH subcarriers along a frequency axis among subcarriers of a predetermined frequency region, and the remaining subcarriers are set to zero power subcarriers. According to the proposal 2 of the present invention, since the power subcarrier spacing becomes N + Γ times the basic subcarrier spacing Δ /, the effective subcarrier spacing becomes (ν + 1) · Δ /. have. Where N is the number of zero power subcarriers between two adjacent non-zero power subcarriers.

The effective subcarrier spacing or the number of null subcarriers inserted may be determined in relation to the magnitude of the Doppler frequency. For example, the number of which is inserted a null subcarrier is a null ratio f of the Doppler frequency / ₄₁ and channel Doppler frequency of a frame structure that requires the insertion of a sub-carrier to a frame structure that does not require insertion of the sub-carriers assumed _d, ₂ ratio, ₂ / / _d / or '/ d / cu' can be determined by multiplying the weight α (positive real number or positive integer).

14 and 15 illustrate an example of operating a flexible frame according to another embodiment of the present invention.

14 is a view comparing CFO influences according to null subcarrier insertion in a CFO generation environment due to the same Doppler frequency.

[159J Referring to FIG. 14, it can be seen that a null subcarrier is inserted between subcarriers in which orthogonality between subcarriers is to be maintained, thereby being robust to the frequency offset caused by the Doppler frequency. That is, according to the present invention, the allowable range of the CFO in which the correct signal can be detected is increased.

15 is a diagram illustrating an effect of inserting a null frequency on a frequency domain signal in the frequency domain.

According to the proposal 2 of the present invention, since a null subcarrier, that is, a zero subcarrier is inserted with a fixed subcarrier spacing in the frequency domain, repetition of the same signal occurs in the time domain. Referring to FIG. 15, it can be seen that the same waveform is repeated according to the number of '0' inserted in the same OFDM symbol period. That is, the same according to the number N (≥ (?) Of null subcarriers inserted between subcarriers to which real data is allocated, that is, between a non-zero power subcarrier and an adjacent non-zero power subcarrier.

The same signal is transmitted N + 1 times (repeated) within an OFDM symbol period. In the proposal 1-2 of the present invention, the subcarrier spacing Δ / is not changed, and the sample is used without change in the period 7 and the sampling frequency / _s . However, as mentioned above, the insertion of a null subcarrier leads to resource loss and a lower rate in the frequency domain. Therefore, the proposal 2 of the present invention may be applied only for a specific situation or purpose, and its application may be limited. For example, the proposal 2 of the present invention may be applied when the link situation due to the Doppler drops sharply, or is applied only for the purpose of maintaining the link connection state. Hereinafter, proposals 2-1 and 2-2 as application examples of the proposal 2 of the present invention will be described.

[163]-Proposal 2-1) The eNB changes the effective subcarrier spacing of a resource allocation region for each UE without changing the subcarrier spacing of a frame according to the Doppler frequency change on the eNB.

In the proposal 2-1 of the present invention, the eNB may apply a flexible frame for each UE in operating the entire frame. In other words, the eNB according to the proposal 2-1 of the present invention may control insertion of a null subcarrier for each UE. This is because, as mentioned above, the proposal 2 of the present invention mitigates or eliminates the effects of the Doppler effect by changing the effective subcarrier spacing by inserting a null subcarrier without changing the subcarrier spacing and the sampling frequency / period. Therefore, since Proposal 2 of the present invention maintains a subcarrier spacing and a sampling frequency / cycle, the eNB of the present invention can adjust the effective subcarrier spacing only for a resource region allocated to the UE for each UE. That is, the eNB may apply the effective subcarrier interval differently according to the channel state of the resource region, that is, the resource allocation region, allocated to the UE. Information about the adjustment of the effective subcarrier spacing and / or the effective subcarrier spacing may be transmitted UE-specifically through a higher layer (eg RRC) signal or UE-specifically via a black physical layer signal (eg PDCCH). have.

Referring to FIG. 16, an eNB or a UE of the present invention can apply a flexible frame according to the present invention by changing an effective subcarrier interval of a resource allocation region allocated differently for each of UE # 0 and UE # 1. For example, if the moving speed of UE # 0 is fast or the Doppler frequency in the resource allocation region for the UE # 0 is large, in the resource allocation region of UE # 0, the moving speed black is determined based on the Doppler frequency. The effective subcarrier spacing is increased by inserting a predetermined number (≥ 1) of consecutive null subcarrier (s) between non-zero subcarriers. For example, if the number of consecutive null subcarriers inserted between two non-zero subcarriers is 1, then the base subcarrier spacing as the non-zero power subcarrier and zero power subcarrier alternate along the frequency axis (ie in the frequency domain) Doppler effect that is not canceled by can be canceled. On the other hand, even with the default (effective) subcarrier spacing, the Doppler effect In case of UE # 0 which can be sufficiently canceled, a null subcarrier is not inserted. When the number of null subcarriers inserted is '0', it can be understood that non-zero power subcarriers and '0' zero power subcarriers alternate. The eNB may transmit frame configuration information for notifying insertion of a null subcarrier and / or the number of null subcarriers inserted. When the eNB notifies the UE of the insertion of null subcarrier (s), in downlink, the eNB inserts null subcarrier (s) between subcarriers in the resource area allocated to the UE and transmits a downlink signal. The UE receives, decodes, or demodulates a downlink signal in the resource region by assuming that there are null subcarrier (s) inserted between the subcarriers of the resource region allocated to the UE. When the eNB notifies the UE of the insertion of null subcarrier (s), in case of uplink, the UE inserts null subcarrier (s) between subcarriers of the resource area allocated to it and transmits an uplink signal. The eNB receives, decodes, or demodulates an uplink signal in the resource region by assuming that there are null subcarrier (s) inserted between the subcarriers of the resource region allocated to the UE. The transmitting end may not map a signal or information to be transmitted to the null subcarrier at all, or may not allocate transmit power to the null subcarrier even when the signal / information is loaded on the null subcarrier. That is, the transmitting end transmits a subcarrier corresponding to a null subcarrier with a transmission power of '0'. The receiver receives, decodes, or demodulates a signal transmitted by the transmitter, assuming that the transmission power of the subcarrier corresponding to the null subcarrier is '0'.

[167] ^■ proposed 2-2) eNB is no sub-carrier interval of the frame changes in accordance with the Doppler frequency change in the link, changes the effective subcarrier spacing in the overall system.

17 illustrates another example of a flexible frame structure according to another embodiment of the present invention.

Proposal 2-2 of the present invention operates the flexible frame by changing the effective subcarrier spacing of the entire frequency resource region. That is, according to the proposal 2-2 of the present invention, when the eNB operates the entire frame, the flexible frame may be applied to the entire frequency region. In other words, the frame structure is changed by changing the effective subcarrier interval in the same manner for all UEs connected to the eNB, not for each UE. Proposal 2-2 of the present invention, like Proposal 2-1 of the present invention, inserts a Doppler by inserting a null subcarrier without changing the subcarrier spacing and the sampling frequency / period. Since the effect is canceled, there is no change factor of the transmission or reception process due to the change of the frame structure.

For example, referring to FIG. 17, when the effective subcarrier spacing needs to be doubled as the Doppler frequency increases, the eNB doubles the effective subcarrier spacing to the UE (s) communicating through the high frequency band. In this case, the subcarrier may be inserted between the subcarriers. In this case, the UE transmits a non-zero subcarrier (i.e., non-zero power subcarrier) and a subcarrier having zero transmit power (i.e., zero power subcarrier) to the entire system band operating at the center frequency linking with the eNB. Transmit or receive signals assuming that are alternately present. The transmitter may transmit the signal after puncturing the signal of the null subcarrier after loading the signal regardless of whether the subcarrier is a null subcarrier or a non-null subcarrier. The receiver assumes that there is no information at all on the null subcarrier, or that information mapped to the null subcarrier is transmitted with zero transmission power and receives a signal in a resource region allocated for the corresponding signal.

In the above-described proposal 2 of the present invention, subcarriers of the frame are arranged along the frequency axis or at every (basic) subcarrier spacing in the frequency domain, and non-zero power subcarriers and N (≥ 0) zero power subcarrier (s). Are placed alternately. If the number of zero-power subcarriers alternating with non-zero power subcarriers is zero, then the effective subcarrier spacing is equal to the base subcarrier spacing.If the number of non-zero power subcarriers and zero power subcarriers is X, then the effective subcarrier spacing is the It will be x times.

In the above-described flexible frame of the present invention, the frame structure is mainly changed in a direction in which the (effective) subcarrier spacing is increased for the case where the Doppler frequency is small and then increased, but the Doppler frequency is large and reduced (effective). It is apparent that the frame structure may be changed in a direction in which the subcarrier spacing is reduced. For example _, the (effective) subcarrier spacing after a change to offset the increase in Doppler frequency.

The frame structure may be altered such that Δ ₂ is a positive integer multiple of the (effective) subcarrier spacing / \ f _\ before the change, and before the change (effective) subcarrier spacing Δ i is changed to correspond to a decrease in the doppler frequency The frame structure may be changed to be a positive integer multiple of the (effective) subcarrier spacing Δ / ₂ . As another example, Δ / ₂ represents a scan! It may have a relationship between the interval 15 kHz, and the product of a power of a positive integer. In other words, 'Δ / ₂ / Δ i = α ^η α is a positive integer, 1 is an integer), but if the Doppler frequency increases beyond a certain range «is a positive integer, the Doppler frequency is out of a certain range When decreasing «is a negative integer, and« may be zero if the Doppler frequency remains constant. In addition, the frame setting information for changing the frame structure type according to an embodiment of the present invention may be transmitted when the Doppler frequency is changed to an inappropriate level for the current frame setting or when there is a frame setting more suitable for the changed Doppler frequency. It may be sent periodically. That is, the eNB may transmit the frame configuration information when the frame structure needs to be changed, but may periodically transmit the frame configuration information. When the frame setting information is periodically transmitted, if there is no sudden change in the Doppler frequency, the frame setting information transmitted at the previous transmission timing and the frame setting information transmitted at the current transmission timing may be the same. For example, when the transmission timing for the frame setting information exists every predetermined period, if there is no sudden change in the Doppler frequency, the (effective) subcarrier spacing Δ l according to the frame setting information of the previous transmission timing is the frame setting of the current transmission timing It may be equal to the (effective) subcarrier spacing Δ / ₂ according to the information. The black may be transmitted as the frame setting information as to whether the frame setting information of the previous transmission timing and the frame setting information of the current transmission timing are the same or not, and only include the parameter (s) corresponding to the frame structure only in other cases. It is also possible to transmit frame setting information.

In the flexible frame operation of the present invention described above, the subcarrier spacing black or the effective subcarrier spacing according to each Doppler frequency may be predetermined according to a specific criterion. For example, Equations 1 to 4 (Effective) subcarriers according to Doppler frequencies can be determined. In the flexible frame operation of the present invention, frame structures according to (effective) subcarrier intervals may be predefined in various ways, and eNB sets UE (s) by setting an appropriate frame structure for each UE, frequency resource region, or cell. Can be notified. Each UE receives frame structure configuration information and adjusts the subcarrier spacing according to the frame structure configuration information, or assumes that null subcarrier (s) is inserted between subcarriers and receives a downlink signal or receives a null subcarrier (s). An uplink signal may be transmitted by being inserted between subcarriers. According to the proposal 1 of the present invention, the subcarrier spacing The sampling frequency, sampling period, FFT size, etc. may be determined according to any one of the embodiments of the proposal 1 of the present invention. According to the proposal 2 of the present invention, even if the effective subcarrier spacing does not change, the actual subcarrier spacing does not change, and thus the sampling frequency, sampling period, FFT size, etc. can be maintained without change.

The flexible frame of the present invention can be applied for a high frequency band. For example, the flexible frame of the present invention can be applied for a frequency band having a center frequency of 20 GHz to 60 GHz.

When carrier aggregation is configured, a frame structure may be configured for each serving CC of the UE. For example, for a UE configured with multiple serving CCs, a frame in which a default subcarrier spacing is used for one serving CC and a base subcarrier spacing for another serving CC is set according to the Doppler effect for each serving CC. It is possible to set a frame in which a large (effective) subcarrier spacing is used.

18 is a block diagram showing the components of the transmitter 10 and the receiver 20 for carrying out the present invention.

The transmitter 10 and the receiver 20 are radio frequency (RF) units 13 and 23 capable of transmitting or receiving radio signals carrying information and / or data, signals, messages, and the like; It is operatively connected with components such as memory 12, 22, RF unit 13, 23, memory 12, 22, and the like, which store various kinds of information related to communication in a wireless communication system, to control the components. And a processor 11, 21 configured to control the memory 12, 22 and / or the RF unit 13, 23 so that the apparatus performs at least one of the embodiments of the invention described above. .

The memory 12 and 22 may store a program for processing and controlling the processors 11 and 21 and temporarily store input / output information. Memory 12, 22 may be utilized as a buffer.

The processors 11 and 21 typically control the overall operation of various models in the transmitter or the receiver. In particular, the processors 11 and 21 may perform various control functions for carrying out the present invention. Processors 11 and 21 may also be referred to as controllers, microcontrollers, microprocessors, microcomputers, and the like. The processors 11 and 21 may be implemented by hardware or firmware, software, or a combination thereof. When implementing the present invention using hardware, the present invention Application specific integrated circuits (ASICs) or digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), etc., configured to perform are provided in the processors 400a and 400b. Can be. Meanwhile, when implementing the present invention using firmware or software, the firmware or software may be configured to include modules, procedures, or functions for performing the functions or operations of the present invention, and the present invention may be performed. The firmware or software configured to be configured may be provided in the processors 11 and 21 or stored in the memories 12 and 22 to be driven by the processors 11 and 21.

The processor 11 of the transmitting apparatus 10 may be configured to encode a predetermined signal and / or data to be transmitted from the processor 11 or a scheduler connected to the processor Π to be transmitted to the outside. After the modulation (modulation) is transmitted to the RF unit (13). For example, the processor 11 converts the data sequence to be transmitted into N _layer layers through demultiplexing, channel encoding, scrambling, and modulation. The coded data string is also called a codeword and is equivalent to a transport block, which is a data block provided by the MAC layer. One transport block (TB) is encoded into one codeword, and each codeword is transmitted to a receiving device in the form of one or more layers. The RF unit 13 may include an oscillator for frequency upconversion. RF unit 13 may include N _t (M is a positive integer greater than 1) transmit antennas.

[1] The signal processing process of the receiving device 20 consists of the inverse of the signal processing process of the transmitting device 10. Under the control of the processor 21, the RF unit 23 of the receiver 20 receives a radio signal transmitted by the transmitter 10. The RF unit 23 may include N _r receive antennas, and the RF unit 23 frequency down-converts each of the signals received through the receive antennas to restore a baseband signal. do. RF unit 23 may include an oscillator for frequency downconversion. The processor 21 may decode and demodulate a radio signal received through a reception antenna to restore data originally intended to be transmitted by the transmitter 10.

The RF unit 13, 23 is provided with one or more antennas. The antenna transmits a signal processed by the RF units 13 and 23 to the outside or receives a radio signal from the outside according to an embodiment of the present invention under the control of the processors 11 and 21. , 23) Perform the function of passing. Antennas are also called antenna ports. Each antenna may correspond to one physical antenna or may be configured by a combination of more than one physical antenna elements. The signal transmitted from each antenna can no longer be decomposed by the receiver 20. The reference signal (RS) transmitted for the corresponding antenna defines the antenna as viewed from the receiver 20's view and includes the antenna whether the channel is a single wireless channel from one physical antenna or not. Regardless of whether it is a composite channel from a plurality of physical antenna elements, the receiver 20 enables channel estimation for the antenna. That is, the antenna is defined such that a channel carrying a symbol on the antenna can be derived from the channel through which another symbol on the same antenna is carried. In the case of an RF unit that supports a multi-input multi-output (MIMO) function for transmitting and receiving data using a plurality of antennas, two or more antennas may be connected.

In the embodiments of the present invention, the UE operates as the transmitter 10 in the uplink and operates as the receiver 20 in the downlink. In the embodiments of the present invention, the eNB operates as the receiving device 20 in the uplink, and operates as the transmitting device 10 in the downlink. Hereinafter, a processor, an RF unit, and a memory provided in the UE will be referred to as a UE processor, a UE RF unit, and a UE memory, respectively, and a processor, an RF unit, and a memory provided in the eNB will be called an eNB processor, an eNB RF unit, and an eNB memory, respectively. .

In the present invention, each node or each transmission point includes an eNB RF unit. In the present invention, nodes participating in carrier aggregation may be managed by one or a plurality of eNB processors. In other words, the cells or CCs participating in the carrier aggregation may be managed by the same eNB processor but may be managed by different eNB processors.

The eNB processor according to the present invention may flexibly change the frame setting according to any one of the embodiments according to the proposal 1 and the proposal 2 of the present invention. The flexible frame according to the first or the second proposal of the present invention may be applied to a specific frequency band, for example, a high frequency band. The eNB processor according to the proposal 1 or the proposal 2 of the present invention controls the eNB RF unit to transmit frame setting information indicating a frame setting for the (effective) subcarrier periodically or when the (effective) subcarrier interval should be changed. can do. The eNB processor according to the proposal 1 of the present invention may change a frame setting having a subcarrier spacing of Δ / l to a frame setting having a subcarrier spacing of Δ / ₂ . The eNB processor is further configured to transmit frame setting information indicating a frame structure to the eNB RF unit indicating a frame setting information black or a subcarrier spacing Δ / ₂ indicating the change of the frame setting. ) May be informed that a frame for communication between the eNB and the corresponding UE (s) should be set according to a frame structure that subtracts the subcarrier spacing Δ / ₂ . The UE processor may cause the UE RF unit to receive the frame setting information. The UE processor is configured to set a frame by changing a subcarrier spacing from ᅀ ᅳ i to ᅀ / ₂ based on the frame configuration information.

The eNB processor and the UE processor according to the proposal 1-1 of the present invention adjust only the subcarrier spacing in the frequency domain, and use the same sampling period in the time domain. According to the proposal 1-1 of the present invention, the system bandwidth of a specific frequency band remains the same even if the subcarrier spacing is adjusted, that is, even if the frame structure is changed. The eNB processor and the UE processor according to the proposal 1-1 of the present invention reduce the FFT size by (ᅀ / ₂ / / ir ¹ times the sampling frequency when the subcarrier spacing increases from ᅀ / i to Δ / ₂ ᅀ / ₂ / i The eNB processor and the UE processor according to the proposal 1-1 of the present invention change the frame setting from the frame setting with the subcarrier spacing Δ / l to the frame setting with the subcarrier spacing Δ / ₂ . The number of OFDM symbols in ΤΤΙ is multiplied by Δ / ₂ / Δ 1 times The eNB processor and the UE processor according to the proposal 1-1 of the present invention may be configured to configure an FFT block according to each FFT size. For example, if the FFT size of the subcarrier spacing _ᅀ / _! Is FFT _slzeA and the FFT sizes of the subcarrier spacing Δ / ₂ are FFT _s , _ze , ₂ , the eNB processor and the UE according to the proposal 1-1 of the present invention are UE. The processor is an FFT of size FFT It is configured to constitute both a block and an FFT block of _size FFT _{size, 2} .

The eNB processor and the UE processor according to the proposal 1-2 of the present invention change the subcarrier spacing in the frequency domain, and change the sampling frequency in the frequency domain and the sampling period in the time domain. However, the eNB processor and the UE processor according to the proposal 1-2 of the present invention are configured to maintain the same FFT size even when the subcarrier spacing is changed. According to the proposal 1 ᅳ 2 of the present invention, when the subcarrier spacing is adjusted, the FFT size is maintained, so that the system BW according to the subcarrier spacing and the FFT size is Change. However, since the base system BW of a specific frequency band is fixed, when the system BW determined according to the subcarrier spacing is larger than the base system BW, in order to cancel the difference between the eNB processor and the UE processor according to 1-2 of the present invention. The subcarriers corresponding to the bandwidth equal to the difference between the system BW and the base system BW determined according to the subcarrier spacing may be set as null subcarriers, and subcarriers far from the center of the specific frequency band may be configured as null subcarriers. . The eNB processor according to the 1-2 of the present invention may be configured not to perform resource allocation to the null subcarriers. The UE processor determines a time-frequency resource to be used for transmission of the uplink signal or reception of the downlink signal based on the resource allocation information from the eNB. The UE processor according to the 1-2 of the present invention may not calculate or generate uplink control information (eg, channel state information) for the null subcarrier Ϊ :.

In the eNB processor and the UE processor according to the proposal 1-2 of the present invention, when the subcarrier spacing increases from ᅀ J to Δ / ₂ and Δ / ₂ / Δ / 1, the sampling frequency is changed to A / ₂ / A / J times. It is configured to change, and the sampling period can be configured to change by (Δ / ₂ / ᅀ ᅳ!) — ¹ times.

The eNB processor according to the proposal 2 of the present invention may be configured to determine an effective subcarrier interval or frame structure. The eNB processor according to the proposal 2-1 of the present invention may be configured to determine an effective subcarrier interval or a frame structure for a resource region allocated to a specific resource region of a specific frequency band. The eNB processor according to the proposal 2-2 of the present invention may be configured to determine an effective subcarrier spacing black frame structure for the entire system BW of a specific frequency band.

The eNB processor according to the proposal 2 of the present invention provides information indicating a determined frame structure or information indicating an effective subcarrier spacing (eg, information indicating the number of subcarriers N + \ corresponding to a non-zero power subcarrier spacing or two pieces of information). The eNB RF unit may be controlled to transmit frame setting information including information indicating the number N of zero power subcarriers set between the (adjacent) non-zero power subcarriers. The eNB processor is non-zero for every N + \ of resource region internal carriers allocated to a specific UE according to Proposal 2-1 of the present invention or subcarriers in the entire system BW of a specific frequency band according to Proposal 2-2. A power subcarrier can be set and a zero power subcarrier can be set between non-zero power subcarriers. The eNB processor does not map a signal to a zero subcarrier, Can be set to '0 ，. The UE processor may cause the UE RF unit to receive the frame setting information. The UE processor applies a frame according to the frame configuration information only to a resource region allocated to a system BW corresponding UE of a specific frequency band according to the proposal 2-1 of the present invention, or according to the proposal 2-2 of the present invention. Can be applied throughout the system BW. The UE processor sets a frame according to the frame configuration information only in a resource region allocated to a corresponding UE among system BWs of a specific frequency band according to the proposal 2-1 of the present invention, or according to the proposal 2-2 of the present invention. Can be set throughout the system BW. In the case of downlink, the UE processor may be configured to receive, decode and / or demodulate a downlink signal assuming that the transmit power of the zero power subcarriers is '0'. In the uplink, a UE processor transmits an uplink signal in an uplink resource region allocated to a corresponding UE, but sets the transmission power of zero power subcarriers in the uplink resource region to '0' to transmit the uplink signal. .

According to the present invention, a frame bonded to channel characteristics of a newly introduced frequency band, for example, a high frequency band, may be set in a future generation communication system, thereby improving system performance.

Industrial Applicability

Embodiments of the present invention may be used in a base station, user equipment, or other equipment in a wireless communication system.

Claims

[Range of request]

[Claim 1]

When the user equipment sets the radio frame,

Receiving frame setting information;

Changing a frame setting from a first frame setting to a second frame setting based on the frame setting information; And

Transmitting or receiving a signal using a frame set according to the second frame setting,

The changing of the frame setting may include setting the number of subcarriers corresponding to a non-zero power subcarrier spacing among a plurality of subcarriers in a frequency domain, from ₂ + r according to the _second frame setting in the number of + subcarriers according to the first frame setting. , Where ^ and N ₂ are each non-negative integers representing the number of consecutive zero-power subcarriers set between two non-zero power subcarriers,

How to set up wireless frame.

[Claim 2]

The method of claim 1,

The subcarrier spacing Δ / ₂ of the frame set according to the second frame setting is the subcarrier spacing Δ / _! According to the first frame setting _. Same as,

The sampling frequency / _{s, 2} of the frame set according to the second frame setting is the same as the sampling frequency according to the first frame setting,

The sampling time r _{s, 2} of the frame set according to the second frame setting is the same as the sampling time r _sj according to the first frame setting,

How to set up wireless frame.

(Claim 3)

The method according to claim 1 or 2,

The frame setting information is applied to a resource region allocated to the user equipment of a specific frequency band,

How to set up wireless frame.

[Reception port 4]

The method according to claim 1 or 2, The frame setting information is applied to the entire system bandwidth of a specific frequency band,

How to set up wireless frame.

[Claim 51]

When the user equipment sets the radio frame,

A processor configured to control the radio frequency (RF) unit and the RF unit,

The processor causes the RF unit to receive frame setting information; Change the frame setting from the crab 1 frame setting to the crab 2 frame setting based on the frame setting information; And causing the RF unit to transmit or receive a signal using a frame set according to the second frame setting,

In order to change the frame setting, the processor determines a number of subcarriers, which are based on a non-zero power subcarrier spacing among a plurality of subcarriers in a frequency domain, according to the first frame setting. N ₂ + r, wherein M and N ₂ are the number of consecutive zero power subcarriers set between two non-zero power subcarriers according to the first frame setting and the second frame setting, respectively. Is a nonnegative integer representing

User device.

[Claim 6]

The method of claim 5,

The subcarrier spacing s / ₂ of the frame set according to the second frame setting is equal to the subcarrier spacing Δ / i according to the first frame setting,

The sampling frequency / _{s, 2} of the frame set according to the second frame setting is the same as the sampling frequency / _{s; 1} according to the first frame setting,

The sampling time T _s , ₂ of the frame set according to the second frame setting is the same as the sampling time according to the first frame setting,

User device.

[Claim 7]

The method according to claim 5 or 6, The processor is configured to apply the frame setting information to a resource region allocated to the user equipment of a specific frequency band,

User device.

[Claim 8]

The method according to claim 5 or 6,

The processor is configured to apply the frame setting information to the overall system bandwidth of a specific frequency band,

User device. ^'

[Claim 9]

In setting the radio frame by the base station,

Send frame setting information;

Changing a frame setting from a first frame setting to a second frame setting according to the frame setting information; And '

And transmitting or receiving a signal by using a frame set according to the second frame setting.

For changing the frame set is a plurality of sub-carriers ratio of the frequency domain - in 'Μ + Γ dog according to the number of subcarriers corresponding to a zero power sub-carrier interval to the first frame set according to the second frame set W ₂ + and r N, wherein N and N ₂ each represent a number of consecutive zero power subcarriers set between two non-zero power subcarriers according to the first frame setting and the second frame setting, respectively. Is an integer,

How to set up wireless frame.

[Claim 10]

The method of claim 9,

The subcarrier spacing Δ / ₂ of the frame set according to the second frame setting is the same as the subcarrier spacing Δ /！ according to the first frame setting,

The sampling frequency / _{s, 2} of the frame set according to the second frame setting is the same as the sampling frequency i according to the first frame setting,

The sampling time T _{s, 2} of the frame set according to the second frame setting is equal to the sampling time！ according to the first frame setting,

How to set up wireless frame.

[Claim 11]

The method according to claim 9 or 10,

The frame setting information is applied to a resource region allocated to a specific user equipment among specific frequency bands.

How to set up wireless frame.

[Claim 12]

The method according to claim 9 or 10,

The frame setting information is applied to the entire system bandwidth of a specific frequency band,

How to set up wireless frame.

[Claim 13]

When the base station sets the radio frame,

A processor configured to control a radio frequency (RF) unit and the RF unit,

The processor causes the RF unit to transmit frame setting information; Change a frame setting from a first frame setting to a second frame setting based on the frame setting information; Causing the RF unit to transmit or receive a signal using a frame set according to the second frame setting,

The processor determines the number of subcarriers in the non-zero power subcarrier interval among the plurality of subcarriers in the frequency domain to change the frame setting according to the second frame setting in Wi + Γ according to the first frame setting. N ₂ + r, wherein 7¼ and N ₂ are the number of consecutive zero power subcarriers set between two non-zero power subcarriers according to the first frame setting and the second frame setting, respectively. Is a nonnegative integer representing

Base station.

[Claim 14]

The method of claim 13,

The processor is configured to apply the frame setting information to a resource region allocated to a specific user equipment of a specific frequency band,

Base station. [Claim 15]

The method of claim 13,

Base station.